Sound amplifier



J. 8. EACH Dec. 20, 1927.

SOUND AMPLIFIER Filed Sent. 4 1926 Inventor:

fumes simpsonBac/i.

Patented Dec. 20, 1927.

JAMES S. BACI-I, OF TORONTQ QNTARIO, CANADA.

SOUND AMPLIFIER.

Application filed September The principal objects of this invention are to enhance the acoustic properties of sound amplifiers used in dispersing the sound waves produced by phonographie or radio reproducers and to devise a construction of amplifying chamber which will separate the sound waves into clearly defined divisions, allowing each division. of waves to amplify to :1 very considerable development by providing an extra long an'ipli'fying passage.

The principal feature of the invention consists in the novel construction and arraugement oil a plurality oit'polygonal tubular casings whereby the sound waves are divided by a pyramidal structure and conducted in clearly defined. separate directions into gradually increasing amplifying chambers.

In the drawingaFigure 1 is a part sectional perspective View of my improved form of amplifier.

Figure 2 is a perspective view showing the parts of the amplifier separated and drawn apart but arranged in their relative position in relation to one another.

Figure 3 is a longitudinal mid-sectional view.

Figure l is a cross sectional view through the line l-t of Figure 3.

In the construction of the device herein shown a casing 1 shaped in the form of the lrustrum of a pyramid and closed at the small end has a central opening 2 in the end 3 and a tube l: extends centrally of the pyramidal casing and is preferably of polygonal shape and gradually expanding to the open end A similar tube 6 of considerably larger dimensions encloses the open ends of the tube 4e and the smaller end of the tube 6 is termed with inwardly curving surfaces from each of the sides forming a pyramidal shaped end 7. The apex of the end 7 is arranged central ot' the large end of the tube i. The sound waves travelling through the tube 1- are thus directed with an outward sweep by curved annularly disposed faces of the pyramidal end.

The sound waves thus diverted from the open end of the tube 4 are directed through the expanding passage 8 around the outside of the tube 4c and within the tube 6.

At the smaller end of the main casing 1 and spaced from the open end 9 of the tube 6 are a plurality of curved surfaces 10 which correspond in number to the sides of 4, 1926. Serial No. 133,606.

the tube a and the casing l and these curve outwardly from the periphery oi? the tube 4; to the inner side of the walls of the casing 1, thus the sound waves that are divided by the pyramidal end '7 of the tube 6 are continued in their direction without the tendency to eddy and the result is that tour streams of sound waves are projected in a parallel direction from the open end of the using 1. i v

The structure as herein shown is extremely simple and theinner tube may, as shown in the drawings, be provided with angular wings 11 which project from the corners thereof into the corners of the tube 6, thus providing a physical means of dividing the spaces into four clearly separated channels. The ends 12 of the wings are curved to fit snugly into the corners of the pyramidal shaped end 7 of the tube 6 and the smaller end of the main casing has fitted thereinto the cup-shaped structure 18 which has wings 14 extending on the diagonal from the corners ot' the pyramidal shaped metal. These diametrical partitions are adapted to receive the open end edges of the large end of the tube 6.

This arrangement of structure forms a very rigid support for the tube 6 and particularly when the wings 11 are used said wings 11 lie flat against the diagonal wings in the cup 13 and they may be secured thereto in any suitable manner desired or they may be merely a snug sliding fit.

A sound amplifier constructed as thus described is extremely simple to construct, can be manufactured at very low cost and it produces very remarkable results in the amplification of sounds produced by a phonograph or other form of diaphragm reproduce).

What I claim as my invention is:

1. .ln a sound amplifier, a polygonal. using having diverging side walls a polygonal tube centrally arranged within saidv casing and having diverging side walls extending towards the open end of the casing. a polygonal tube spaced from the aforesaid tube and arranged within said. casing and curved walls disposed opposite the diverged ends of said tubes receiving the sound waves therefrom and directing them backwardly and forming with said tubes and easing continuous progressively expanding chambers.

2. A sound amplifier, comprising a polygonal casing having diverging side walls, a polygonal. tube supported centrally within said casing, having side walls diverging in the same direction as the walls of said casing, a polygonal tube inserted over the aforesaid tube and spae d therefrom and having side walls diverging toward the small end of saideasing, said latter tube having a pyramidal-shaped end, the point of which extends into the large open end of the central tube, and a plurality of curved deflectors arranged at the large inward end of the other tub-e directing the sound waves outwardly into the main casing.

A sound amplifier, comprising a casing having four diverging walls, a tube supported centrally and extending longitudinally of said casing toward the open end, said tube having Iour walls diverging in the same direction as said casing and tern'1i nating in an open end, a plurality of wings extending diagonally from the corners of said casing, a tour-sided tube having walls diverging in a direction opposite to those of the casing and said torl'ner tube and adapted to lit over said wings and having a pyramidal-shaped end curving from the walls thereof imvardly to an apex arranged in axial alignment with and opposite the large end of the inner tube, and a metal cup having tour curved walls fitting snugly around the inner tube and sweeping outwardly to the walls of the casing, and diagonal partitions in said cup engaging the large open end of the intermediate tube and supporting it therein.

t. Ina sound amplifier, a casing having diverging side walls, a tube centrally arranged within said casing and having diverging-side walls extending toward the open endo'l the casing, a tube spaced from the aforesaid tube and arranged within said casing, curved walls disposed opposite the diverged ends of said tubes receiving the sound waves therefrom and directing thein backwardly and forming with said tubes and casing continuous progressively expanding chambers, and a plurality of radial partitions extending longitudinally of said chambers.

JAMES S. bACll. 

